Switching regulators are a type of power supply that exploit the energy storage properties of inductors and capacitors to receive an input voltage and step up, step down, or otherwise regulate an output voltage. In a switching regulator, during a first time span an inductor may have up to the full, unregulated input voltage applied across it. During this first time span, the inductor's current builds up, storing
      1    2    ⁢      LI    2  of energy in its magnetic held. During a second time span, energy is transferred from the inductor to a filter capacitor, which smooths the output. When a grounded switch is placed between the inductor and the capacitor, opening and closing the switch alternates between the foregoing first time span and second time span. A control law may be used to compute the optimal switching frequency for the switch to provide a smooth output waveform at the desired voltage.